Magnetic sound translating system



arch 23 1948" w. P, LEAR MAGNETIC SOUND TRANSLATING SYSTEM Filed May 22, l94-5 4 Sheets-Sheet l 23, 1948 w. P. LEAR EBA-38 222 MAGNETIC SOUND TRANSLATING SYSTEM Filed May 22, 1945 4 Sheets-Sheet Z Marsh 23, 11948. p R

MAGNETIC SOUND TRANSLATING SYSTEM Filed May 22, 1945 4 Sheets-Sheet 3 IN V EN TOR.

math 23 N. LEAR Filed May 22, 1945 MAGNETIC SOUND TRANSLATING SYSTEM Sheets-Sheet 4 ATTORNEY Patented Mar. 23, 1948 UNITED STATES PATENT OFFICE by mesne cuts, to Lear, Incorporated, .Grand Rapids, Mich., a corporation of Illinois Application May 22, 1945, Serial No. 595,240 20 Claims. (Cl. 179-1002) 1 This invention relates to magnetic recording systems and more particularly to a magnetic sound translating unit for used in a magazine type recording system.

The present sound translating unit is particularly adaptable for use with the magazine described and claimed in my copending application Serial No. 593,378 filed May 12, 1945, now Patent No. 2,424,697, issued July 29, 1947, for Magnetic recorder, and assigned to the same assignce as is this case. As described in said copending application, the magazine contains a pair of spaced reels for traversing a linear magnetic recording medium, such as a magnetic wire, with respect to a magnetic translating head, and also contains spooling mechanism for winding the wire in layers onto and oif the reels.

The unit of the present invention comprises driving mechanism and electronic sound translating components cooperable respectively with the driving and spooling mechanism of such magazine and with the magnetic translating head thereof. The unit of the present invention may be used for either recording or reproducing sound, and includes novel combined electrical and mechanical controls for selectively conditioning the recording system for rewinding, sound recording, or sound reproducing.

It is among the objects of this invention to provide a sound translating unit for use with a magazine type magnetic recording system; to provide such a sound translating unit interchangeably cooperative with any one of a plurality of magazines containing a magnetic recording medium and reels for traversing the same with respect to a magnetic recording head; to provide such a unit including means for automatically stopping the reel driving mechanism when the wire in the magazine has been completely rewound from one reel onto the other reel; to provide such a sound translating unit including a novel control unit for electrically and mechanically conditioning the translating unit for either recording or reproducing sound or for rewinding the recording medium onto a rewind reel in the magazine; to provide such a translating unit including gear reduction means associated with the reel driving mechanism for operating spooling mechanism in the magazine at a reduced rate of speed with respect to the reel driving means; to provide such a unit including latching means automatically engageable with a magazine when the latter is placed in cooperative relation with the translating unit; and to provide a simple, easily serviced, light weight sound translating unit for use with a.

magazine type recording system.

These and other objects, advantages and novel features of the invention will be apparent from the following description and the accompanying drawings. In the drawings:

Fig. 1 is a perspective view illustrating the unit of the invention having a magazine engaged therewith.

Fig. 2 is to top plan view of a translating unit of the invention.

Fig. 3 is a vertical sectional view through the translating unit of the invention and a magazine associated therewith.

Fig. 4 is a bottom plan view of a driving mechanism forming part of the invention.

Fig. 5 is a transverse sectional View on the line 5-5 of Fig. 3.

Fig. 6 is a transverse sectional view on the 20 line 6-6 of Fig. 3.

Fig. 7 is an elevational view, partly in section, on the line 1-1 of Fig. 6.

Fig. 8 is an elevational view, partly in section, on the line 88 of Fig. 6.

Fig. 9 is an elevational view, partly in section, on the line 9-9 of Fig. 5.

Fig. 10 is a schematic wiring diagram illustrating the motor control circuit of the unit.

Fig. 11 illustrates the indicating and switch 30 operating mechanism.

Referring to the drawings, the sound translating unit l5 of the invention is shown in Fig. 1 as arranged with a magazine in cooperative relation therewith. Unit I5 includes a base section I 6, having a front panel I 1, and a cover l8. Cover I8 is apertured as at 2| to expose a mounting plate 22 on which magazine 20 is placed.

Front panel l6 includes the controls for the unit such as a switch 23, a power connection 24, an indicating light 25, a jack 26 adapted to receive a plug connected to a microphone, an electro-mechanical control unit operating lever 21, and knobs 30, 3|, 32 and 33 controlling operation of electrical and electronic components of the unit. A grill 34 conceals a loud speaker 39 incorporated in the unit.

As explained above, the unit of the present invention is particularly adapted to cooperate with a magazine 20 of the type described and claimed in my said copending application. Referring to Figs. 1 and 3, magazine 20 includes a base 35 having a cover 36 detachably secured thereto by screws 31, and provided with an aperture 38 containing a transparent window through which in- 55 dicating mechanism registering the amount of 10 portion of the from unit l5, by bowed springs 3 talking time available may be observed. Such indicating mechanism is described and claimed in my said copending application.

, Magazine 28 contains a pair of reels 48 and 4| interchangeably receiving a magnetic recording wire 45 and secured to shafts 42 and 43 mounted on bearings in upstanding bosses 44 and 46 of base 35. On the lower end of each shaft 42, 43 is a coupling gear 41, 48, respectively detachably engageable with coupling gears 58 and 5| of unit l5. Coupling gears 41, 48, 58 and 5| are of the type described and claimed in my said copending application; Reels 48 and 4| are restrained against rotation, when magazine 28 is disengaged 52 and 53 secured to bosses 44 and 46. Normally, these springs engage the reels to hold the same stationary, and maintain wire 45 taut. When magazine 28 is engaged with unit l5, pins 54 and 55 on the unit enter apertures in the magazine to engage springs 52 and 53 respectively and compress the same out of engagement with the reels to provide for free rotation of the latter.

Reels 48 and 4| traverse wire 45 with respect to a magnetic translating head generally indicated at 68. Magazine I5 is further provided with transversally extending pins 56 at each corner thereof, which are engaged with pairs of latch bars 51, 58 in unit l5 to retain magazine 28 engaged with unit l5.

Referring to Figs. 2 and 3, a release bar 6| projects above the upper surface of cover l8 and is secured to a latch bar 58. Bars 51 and 58 are pivotally mounted at 62 and 63 respectively. A

link 64 is pivotally interconnected to bar 51 above its pivot point and to bar 58 below its pivot point. Accordingly, when latch bar BI is depressed, both bars 51 and 58 are moved inwardly to release pins 56 and permit magazine 28 to be disengaged from unit l5.

Unit i5 is more particularly shown in Figs. 2 through 9. Base portion I6 is provided with a central recess shown at 65 in'Fig. 3 in which is secured a base plate 66, through coupling means indicated at 61. On either side of recess 65, electrical and electronic sound translating components may be mounted on base portion l6. A pair of pillars 68 and 18 interconnect base plate 66 to mounting plate 22. Base plate 66, as will be described more fully hereinafter, supports the driving mechanism for rotating coupling gears 58 and 5| and also for operating a spooling drive gear for the spooling mechanism in magazine 28.

Mounting plate 22, as previously explained, supports magazine 28. For this purpose, the mounting plate is formed with apertures 1| at each corner through which latching bars 51 and 58 project. These bars are interconnected in the same manner as described for the sound translating unit illustrated in my said copending application. Mounting plate 22 also is formed with apertures through which project coupling gears 58 and 5|. These gears are provided with axially extending teeth having rounded outer edges for engagement with similarly formed coupling gears 41 and 48 of magazine 28. An electrical connection member such as a socket 12 is mounted on plate 22 for engagement with a suitable mating electrical connection member in magazine 28. Near its rearward edge, as viewed in Fig. 2, plate 22 is formed with an aperture 13 through which projects the operatingiarm 14 of a limit switch mechanism described more fully hereinafter. Immediately forward and to one side of aperture 13, an aperture 15 provides for projection of a 4 spooling mechanism drive gear 16 which cooperates with a similar gear in magazine 28 to operate spooling mechanism, elapsed time indicating mechanism and limit switch operating mechanism therein. The gear in magazine 28 drives a mechanism for level winding of the wire onto the respective spools depending upon whether the machine is recording and reproducing or rewinding. Such level layer winding means constitutes no part of the present disclosure and insofar as the instant case is concerned, such level winding means may take any of several forms known in the art and driven' by gear 16. However, the gear 16 also drives the switching mechanism shown particularly in Figs. 10 and 11.

The driving mechanism in unit l5 for the reeling, spooling and indicating means of magazine 28 is shown more particularly in Figs. 3 through 6, and is motivated by a motor 88 which is mounted on a supporting plate 11 secured to base plate 66. The motor may be of the constant speed type customarily used for operating the turntables or electric phonographs and is provided with a friction driving roller 18 projecting beneath base 66. Roller 18 is selectively operable to drive either reel 48 or reel 4| through mechanism generally indicated at (Fig. 4)

Pillar 68 is a hollow tubular member having upper and lower flanges 8| and 82 respectively secured to mounting plate 22 and base member 66, and contains bearings 83, 83 rotatably supporting a shaft 84 to secured for rotation. Gear 58 is movable axially of shaft 84 being normally urged outwardly by a spring 86. The gear may thus move inwardly when magazine 28 is engaged with unit i5, to provide intermeshing engagement with coupling gear 41 of the magazine in the event that there may be slight angular misalignment of the coupling gears. The rounded edges of the axially extending teeth of the gears facilitate this intermeshing engagement. Shaft 84 has a reduced portion 81 extending beneath base 66, and a hub member 88 is keyed to such reduced portion. A friction driving wheel 88 is mounted on hub 88 and a nut 9| secured to a threaded end 92 of shaft 84 maintains the hub and friction wheel assembled therewith.

Pillar 18 is likewise tubular and has a lower flange 83 secured to base 66 and an upper flange 94 secured to a gear housing 85. Bearings 96, 86 in pillar 18 rotatably support a shaft 81 having a reduced end 98 extending beneath base 66. A friction driving wheel I88, larger in diameter than driving wheel 98, is keyed to reduced portion 88 of shaft 91 and held thereon by a nut |8| threaded on the lower end N2 of shaft 81. Wheel I88 has a hub |83 to which is secured a friction collar I84 for a purpose to be described hereinafter.

The upper end of shaft 91 is reduced in diameter as indicated at I85 and coupling gear 5| is secured thereto for rotation with the shaft while being axially movable thereof. A spring I86 urges coupling gear 5| outwardly through an aperture in mounting plate 22.

Beneath gear 5|, a, spiral gear W1 is secured to shaft 81 and meshes with a spiral gear |88 on a shaft 8 extending at right angles to shaft. 91. A worm III on shaft 8 engages a worm wheel H2 on a shaft H3 extending at right angles to shaft H8. Shaft H3 is suitably mounted in a bracket 4 forming part of gear housing 85. Spooling mechanism driving gear 16 is secured to the rearward end of shaft 3. Due to the speed which coupling gear 58 is I reduction aflorded by gears I01, I08, worm III and worm wheel II2, gear 16 is rotated at a considerablyreduced rate with respect to the rate of rotation of coupling gear 6|. The spooling mechanism and associated elements in magazine 20 are thus operated at a reduced rate with respect to the rate of rotation of the reels in the magazine.

A bracket 5 is adiustably mounted on the lower side of base member 66. For this purpose, the bracket is provided with apertures II 6 and H6 through which extend fastening members H1, H1 which are of less diameter than the lateral dimensions of apertures II6. Bracket .II5 is therefore movable both'laterally and longitudinally of base member 66.

Bracket member II5 rotatably supports an in.- termediate friction driving wheel I20 selectively engageable with driving roller 18 and with either driving wheel 90 or I00. Such selective engagement is provided by a combined rearward movement of bracket H5 and oscillation thereof from the position shown in Fig. 4, all in a manner to be described. A pair of arms I2I and I22 extend from either end of bracket I I5 and support braking shoes I23, I24, which, in the inoperative positionofthemechanismshowninFig. 4, are engaged with driving wheels 90 and I respectively to maintain the same against rotation. For a purpose to be described, bracket H is further provided with a pair of depending abutments I26 and I21 extending obliquely on either side of the pivot support of intermediate driving wheel I2 0.

A pair of cooperating juxtaposed brackets I25 and I30 are commonly pivoted to the underside of base plate 66 by a stud I28. Adjacent its rearward end, bracket I25 is provided with depending ears I3I and I32 in which are adjustably mounted studs I33 and I34 provided with lock nuts I35. Upon swinging movement of bracket I25 in either direction, one of the studs I33 or I34 will engage one f the'abutments I26 or I21 on bracket 5 to move the bracket rearwardly and oscillate it in one direction or the other. Adjacent its intermediate portion bracket I25 is provided with a pair of lugs I36 and I31 to which are secured leaf springs I38 and I40 respectively. Brake shoes MI and I42 are secured on the outer end of leaf springs I38 and I40, and in the position shown in Fig. 4, are in engagement respectively with hub 88 associated with driving wheel 90 and with collar I04 on the hub of driving wheel I00. The purpose of this arrangement will be apparent as the description proceeds.

Near the forward end of bracket I25, a flange I43 depends therefrom through an arcuate slot I44 in bracket I 30, and is connected by a coil spring I45 to the pivotal mounting I 49 of intermediate driving wheel I 20 to normally urge bracket H5 and its component elements to the forward position shown in Fig. 4. An upwardly extending flange I46 on the forward end of bracket I25 has secured thereto an upwardly and rearwardly bowed spring I41, on the inner end of which is a locking piece I48 having a, depending detent I5I (Fig. 7) extending into a cam slot I52 in bracket I 30. In the position shown in the drawings, detent I5I is engaged with the central notch of a latching member I53 secured to the forward wall I49 of base 66.

Bracket I30 is provided with a depending portion I54 to which control lever 21 is detachably secured for projection beyond front panel I6 of unit I5, and with depending lugs I54 and I55 6 connected by springs I60 and I51 flange I 43 of bracket I25.

The operation of the mechanism so far described is as follows. When control switch 23 is in the on position, motor 00 is continuously energized to rotate driving roller 18. With the control lever 21 in the intermediate position, intermediate driving wheel I20 is out of engagement with roller 18 and also out of engagement with driving wheels 00 and I00. The mechanism then occupies the position shown in Fig. 4.

Brackets I25, I30 form a lost motion connection between selector lever 21 and mechanism 85. If lever 21 is moved to the "rewind position, bracket I30 is oscillated clockwise as viewed in Fig. 4. and during the initial movement of bracket respectively to I30, no displacement of mechanism 85 occurs.

However, as bracket I30 movement, spring I 56 is tensioned and cam slot I52, engaging detent I5 I, releases the detent from its engagement with the intermediate notch of member I53. When detent I5I is released from the intermediate slot, the tension of spring I56 snaps bracket I25 in the clockwise direction until detent I5I engages the right hand notch (Fig. 4) of member I53.

Such clockwise movement of bracket I25 decreases the pressure with whicnbrake member I4I engages hub 88 and increases the pressure with which brake member I42 engages braking collar I04. Stud I34 thereupon engages ear I21 to move bracket II5 rearwardly and oscillate bracket II5 a slight amount in the clockwise direction. This releases shoes I23 and I24 from engagement with driving wheels and I00 respectively. Intermediate driving Wheel I20 is then engaged with driving roller 18 and with rewind driving roller 90. Rewind reel 40 is thus rotated in a direction to rewind wire 45 thereon, and at a relatively high rate of speed.

The unwinding of wire 45 from storage reel 4I effects rotation of this reel which, through coupling gears 40 and SI rotates shaft 91. Through the reduction gearing previously described, gear 16 is thus rotated to operate the spooling mechanism and associated components in magazine 20. but at a reduced rate with respect to the rate of movement of wire 45. In a, manner to be described, when substantially all of wire 45 has been rewound on wheel 40, motor 80 is automatically 'deenergized. In a similar manner, if control lever 21 were moved to the right as viewed in Figs. 1, 2 and 3, or to the left as viewed in Fig. 4, to the recording and reproducing position, intermediate driving wheel I20 would be engaged with driving roller 10 and with storage wheel I00 to wind wire 45 onto storage reel 4!.

Normally motor 80 is energized for rotation in a direction to operate "storage reel M to wind wire 45 thereon. Movement of bracket I 25 into the rewind position operates switch mechanism to reverse the direction of rotation of motor 80 so that the motor will rotate rewind reel 40 in the correct direction to rewind wire 45 thereon. For this purpose, a switch unit I60 is mounted on base 66, and comprises a plurality of snap action switches indicated at I58 and I6I. Referring more particularly to Figs. 5, 6 and 8, switches I58 and I6I are operable by a cam I62 pivoted on bracket I63 secured to wall I49 of base plate 66. A leaf spring I64 is secured to cam I62 for engaging the operating plungers of switches I58 and NH. Cam I62 is formed with a depending ear I65 extending into an aperture I66 in bracket I25 adjacent flange I43. Movement of continues its clockwise 7 bracket I25 in response to movement of lever 21 to the "rewind position operates cam I62 through ear I65 to in turn operate switches I58 and I6I from the position shown in Fig. 8 to the opposite position. This operation conditions motor 80 for operation in the reverse direction.

Means are provided for interrupting operation of the driving mechanism when wire 45 is completely rewound from one reel of the magazine onto the other. For this purpose, a bracket I18 is secured to the under surface of plate 22 near its rearward edge as viewed in Fig. 2. Referirng more particularly to Figs. and 9, bracket I10 supports a pair of snap action limit switches HI and I12 controlling energization of motor 80 in either direction. A T-shaped operating member 14 is pivotally mounted at I13 on bracket I10 and has secured to each end leaf springs I14, I15 engaging the operating plungers of switches I1I, I12. A pair of coil springs I16, I16 normally maintain the operating member 14 in the neutral position.

Operating member 14 projects above the surface of plate 22 and through a s1ot I11 in a laterally movable member I18 in magazine 20. Member I18 is movable along magazine 20 by means including gearing connected to the spooling mechanism driven by gear 18, all as described in my said copending application. Adjacent either limit of movement of wire 45, abutment means engage member I18 to move the same to the right or left, as viewed in Fig. 9, to correspondingly pivot member 14 and open one of the switches I1I or I12 to deenergize motor 80. Movement of laterally movable member I18 is effected by the mechanism shown in Figure 11. In this view laterally movable member I18 comprises the bent-up ears I85 and I86. Ear I85 is equipped with the adjustable abutment I81. Either ear I86 or adjustable abutment I81 is disposed to be engaged by nut I88 which is driven by threaded shaft I89. Nut I88 moves laterally along the shaft I89 and is locked against rotation by sliding engagement with a suitable surface. Shaft I89 is rotatably supported in pillow blocks I90 and I8l and is driven by bevelled gear I92. Beveled gear I92 in turn receives its operating torque from mating beveled gear I93. Beveled gear I83 is driven by a gear 15a on the same shaft meshing with gear 16, the gear ratio therebetween being such that a predetermined speed ratio exists between the revolutions of the shaft 91 and of the gear I93.

Fig. 10 diagrammatically illustrates 'the operation of switches I58, I6I, HI and I12 in controlling the operation of motor 80. For purposes of illustration, motor 80 is shown as a shunt wound motor comprising an armature I88 and a shunt field winding I82 energized from a suitable source of electric current indicated by terminals I83,

' I84. The several switches are shown in the position they normally occupy when the selector 14 is in the neutral position. As explained, under such circumstances, motor 88 is energized for rotation in a direction to wind the recording wire on storage? reel M for recording and reproducing. When selector 14 is thrown to the rewind position, flange I43 engages ear I65 to swing cam I62 counterclockwise reversing the position of switches I58 and "SI. The motor is then energized for rotation in a direction to rewind recording wire 45 on rewind reel 40.

Limit switch I1I controls the limit of operation of motor 80 during the recording and reproducing operation. When substantially all of wire 45 has type recording system. The unit includes a novel been wound onto reel 4I, member I18 engages selector I4 and swings it in a counterclockwise direction to open switch I1I. This breaks the circuit of motor 80. However, when switches Ill and IBI are moved to the reverse position for rewinding wire 45, the energization of 'motor is under the control of switch I12 which remains closed until such time as wire 45 has been substantially all rewound on reel 40. At such time, member I18 is moved-to the right to swing selector 14 in a clockwise direction and open switch The described mechanism comprises an emcient, compact and easily serviceable sound recording or reproducing unit for use in a magazine electromechanical control unit for conditioning the apparatus either for rewinding or for recording and reproducing. Furthermore, limit switch means are provided for automatically deenergizing the driving means when the magnetic recording wire has been substantially completely rewound from one reel to the other. Novel means are also provided for insuring that the wire is maintained in tension in either direction of movement.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles thereof, it will be understood that the invention may be otherwise embodied without departing from such principles.

What is claimed is:

1. Magnetic sound translating apparatus comprising, in combination, a pair of rotatable reels for traversing a linear magnetic recording medium with respect to a magnetic translating head; a pair of driven members, each mechanically coupled to one of said reels, said driven members being spaced from each other; a driving member selectively movable into driving engagement with either of said driven members; and mechanism for selectively engaging said driving member with either of said driven members, said prising, in combination, a pair of rotatable reels for traversing a linear magnetic recording medium with respect to a magnetic translating head; a pair of driven members, each mechanically coupled to one of said reels, said driven members being spaced from each other; a driving member selectively movable into driving engagement with either of said driven members: driving means normally disengaged from said driving member; and mechanism forselectively engaging said driving member with either of said driven members and with said driving means, said mechanism including a movable selector, a movable operator operative to selectively engage said driving member with either of said driven members and with said driving means, resilient means biasing said operator to follow the movement of said selector and means restraining movement of said operator in response to movement or said selector until said selector has approached its limit of movement in either direction, said last-named means thereupon releasing said operator to be biased in the same direction by said resilient means.

3. Magnetic sound translating apparatus comprising, in combination, a pair of rotatable reels for traversing a linear magnetic recording medium with respect to a magnetic translating head; a pair of driven members, each mechanically coupled to one of said reels, said driven members being spaced from each other; a driving member selectively movable into driving angagement with either of said driven members; normally ineifective brake means selectively operable on either of said driven members; and

, mechanism for selectively engaging said driving member with either of said driven members, said mechanism including a movable selector, a movable operator operative to selectively engage said driving member with either of said driven members and to render said brake means effective on the other driven member, resilient means biasing said operator to follow the movements oi. said selector and means restraining movement of said operator in response to movement of said selector until said selector has approached its limit of movement in either direction, said last-named means thereupon releasing said operator to be biased in the same direction by said resilient means.

4. Magnetic sound translating apparatus comprising, in combination, a pair 01. rotatable reels for traversing a linear magnetic recording medium with respect to a magnetic translating head; a pair of driven members, each mechanically coupled to one of said reels, said driven members being spaced from each other; a driving member selectively movable into driving engagement with either of said driven members; a pair of brakes each normally engaged with one of said driven members; and mechanism for selectively engaging said driving member with either of said driven members, said mechanism including a movable selector, a movable operator operative to selectively engage said driving member with either of said driven members and to disengage both of said brakes, resilient means biasing said operator to follow the movements ofsaid selector and means restraining movement of said operator in response to movement of said selector until said selector has approached its limit of movement in either direction, said last-named means thereupon releasing said operator to be biased in the same direction by said resilientmeans.

5. Magnetic translating apparatus comprising, in combination, a pair of rotatable reels for traversing a linear magnetic recording medium with respect to a magnetic translating head; a pair of driven members, each mechanically coupled to one of said reels, said driven members being spaced from each other; a driving member selectively movable into driving engagement with either of said driven members; a pair of brakes each normally engaged with one of said driven members normally inefifective brake means selectively operable on either of said driven mem bers; and mechanism for selectively engaging said driving member with either of said driven members, said mechanism including a movable selector, a movable operator operative to selectively engage said driving member with either of said driven members, to disengage both of said brakes and to render said brake means efiective 6. Magnetic sound translating apparatus comprising, in combination, a pair of rotatable reels for traversing a linear magnetic recording medium with respect to a magnetic translating head; a pair of driven members, each mechanically coupled to one of said reels. said driven members being spaced from each other; a driving member selectively movable into driving engagement with either of said driven members; driving means normally disengaged from said driving member; a pair of brakes each normally engaged with one of said driven members; normally ineffective brake means selectively operable on either of said driven members; and mechanism for selectively engaging said driving member with either of said driven members, said mechanism including a movable selector, a movable operator operative to selectively engage said driving memberawith either of said driven members and with said driving means, to disengage both of said brakes and to render said brake means effective on the other driven member; resilient means biasing said operator to follow the movements 01' said selector and means restraining movement of said operator in response to movement of said selector until said selector has approached its limit of movement in either direction, said lastnamed means thereupon releasing said operator to be biased in the same direction by said resilient means.

'7. Magnetic sound translating apparatus comprising, in combination, a pair of spaced rotatable reels for traversing a linear magnetic recording medium with respect to a magnetic translating head; a pair of rotatable driven members, each mechanically coupled to one of said reels, said rotatable driven members being spaced from each other; a rotatable idler selectively movable into driving engagement with either of said driven members; a rotatable driving member normally disengaged from said idler; an electric motor coupled to said driving member; a movable selector; a movable operator operative to selectively engage said idler with either of said rotatable driven members; resilient means biasing said operator to follow the movements of said selector; means restraining movement of said operator in response to movement of said selector until said selector has approached its limit of movement in either direction, said last-named means thereupon releasing said operator to be biased in the same direction by said resilient means; and

mechanism coupled to one 01 said driven mem-- bers and operable automatically in response to a predetermined number of revolutions of one of said reels to eiIect deenergization of said motor.

means- 11 members; a rotatable drivlng'member normally disengaged from said idler; an electric motor coupled to said driving member; a movable selector; a movable operator operative to selectively engage said idler with either of said rotatable driven members; brake means movable by said operator into effective engagement with the other driven member; resilient means biasing said operator to follow the movements oi said selector; means restraining movement of said operator in response to movement of said selector until said selector has approached its limit of movement in either direction, said last-named means thereupon releasing said operator to be biased in the same direction by said resilient means; and mechanism coupled to one of said driven members and operable automatically in response to a predetermined number of revolutions of one of said reels to efiect deenergization of said motor.

9. Magnetic sound translating apparatus comprising, in combination, a pair of spaced rotatable reels for traversing a linear magnetic recording medium with respect to a magnetic translating head; a pair of rotatable driven members, each mechanically coupled to one of said reels, said rotatable driven members being spaced from each other; a pair oi brakes each normally engaged with one of said driven members; a rotatable idler selectively movable into driving engagement with either of said driven members; a rotatable drivin member normally disengaged from said idler; an electric motor coupled to said driving member; a movable selector; a movable operator operative to selectively engage said idler with either of said rotatable driven members and to disengage both of said brakes; resilient means-biasing said operator to follow the movements of said selector; means restraining movement of said operator in response to movement of said selector until said selector has approached its limit of movement in either direction, said last-named means thereupon releasing said operator to be biased in the same direction by said resilient means; and mechanism coupled to one of said driven members and operable automatically in response to a predetermined number of revolutions of one of said reelsto effect deenergization of said motor.

10. Magnetic sound translating apparatus comprising, in combination, a pair of spaced rotatable reels for traversing a linear magnetic recording medium with respect to a magnetic translating head; a pair of rotatable driven members, each mechanically coupled to one of said reels, said rotatable driven members being spaced from each other; a pair of brakes each normally engaged with one of said driven members; a rotatable idler selectively movable into driving engagement with either of said driven members; a. rotatable driving member normally disengaged from said idler; an electric motor coupled to said driving member; a movable selector; a movable operator operative to selectively engage said idler with either of said rotatable driven members and to disengage both of said brakes; brake means movable by said operator into efiective engagement with the other driven member; resilient means biasing said operator to follow the movements of said selector; means restraining movement of said operator in response to movement of said selector until said selector has approached its limit of movement in either direction, said last-named means thereupon releasing said operator to be biased in the same direction b said resilient means; and mechanism coupled to one of said driven members andoperable automatically in response to a predetermined number of revolutions 01' one of said reels to eil'ect deenergization of said motor.

11. Magnetic sound translating apparatus comprising, in combination, astorage reel and a rewind reel for traversing a linear magnetic recording medium with respect to a magnetic translating head; a pair of rotatable driven members, each mechanicallycoupled to one of said reels, said rotatable driven members being spaced from each other; a rotatable idler selectively movable into driving engagement with either of said driven members; a rotatable driving member normally disengaged from said idler; an electric motor coupled to said driving member; a selector movable from a neutral position to a first "recording and reproducing" position or to a second rewind position; a movable operator operative to selectively engage said idler with said driving member and with either the driven member coupled to the storage reel or the driven member coupled to the rewinding reel dependent upon movement of said selector to either said first position or said second position; means biasing said operator to follow the movements of said selector; a switch operable to reverse the direction of rotation of said motor; and an element coupled to said operator and effective to operate said switch to reverse said motor when said selector is moved to said second position.

' 12. Magnetic sound translating apparatu comprising, in combination, a storage reel and a rewind reel for traversing a linear magnetic recording medium with respect to a magnetic translating head; a pair of rotatable driven members,

each mechanically coupled to one of said reels, said rotatable driven members being spaced from each other; a rotatable idler selectively movable into driving engagement with either of said driven members; a rotatable driving member normally disengaged from said idler; an electric motor coupled to said driving member; a selector movable from a neutral position to a first "re cording and reproducing" position or to a second rewind" position; a movable operator operative to selectively engage said idler with said driving member and with either the driven member coupled to the storage reel or the driven member coupled to the rewinding reel dependent upon movement of said selector to either said first po-' sition or said second position; resilient means biasing said operator to follow the movements of said selector; means restraining movement of said operator in response to movement of said selector until said selector has approached its limit of movement in either direction, said last-named means thereupon releasing said operator to be biased in the same direction by said resilient means; an element coupled to said operator and efiective to operate said switch to reverse said motor when said selector is moved to said second position; and mechanism coupled to one of said driven members and operable in response to a predetermined number of revolutions of one of said reels to efiect deenergization of said motor.

13. Magnetic sound translating apparatus comprising, in combination, a pair of spaced rotatable reels for traversing a linear magnetic recording medium with respect to a magnetic translating head; a supporting plate; a pair of friction driven wheels rotatably mounted on said plate and each operatively coupled to one of said reels; a manually operable selector pivotally secured to said plate intermediate said reels; a bracket pivotally mounted on said plate, said selector and said bracket having a common pivot center; resilient .ing one of said brake means means biasing said bracket to follow the movements of said selector: a latch fixed to said plate; a latching bar on said bracket releasably engaging said latch, said latch and bar preventing movement of said bracket in response to movement of said selector; a cam on said selector engaging said latching bar, said cam releasing said bar from said latch when said selector approaches its limit of movement in either direction, whereupon said resilient means bias said bracket into substantial coincidence with said selector; a driving roller rotatabl mounted on said plate; an electric motor coupled to said driving roller; an idler wheel movably mounted on said plate intermediate and normally out of engagement with said driven wheels; means normally maintaining said idler wheel out of engagement with said driving roller; and mechanism operable by movement of said bracket under the influence of said resilient means to engage said idler wheel with said driving roller and selectively with one of said driven wheels.

14. Magnetic sound translating apparatus comprising, in combination, a pair of spaced rotatable reels for traversing a linear magnetic recording medium with respect to a magnetic translating head; a supporting plate; a pair of friction driven wheels rotatably mounted on said plate and each operatively coupled to one of said reels; a manually operable selector pivotally secured to said plate intermediate said reels; a

bracket pivotally mounted on said plate, said selector and said bracket having a common pivot center; a pair of brake means mounted on said bracket and each cooperable with a driven wheel; resilient means biasing said bracket to follow the movements of said selector; a latch fixed to said plate; a latching bar on said bracket releasably engaging said latch, said latch and bar preventing movement of said bracket in response to movement of said selector; a cam on said selector engaging said latching bar, said cam releasing said bar from said latch when said selector approaches its limit of movement in either direction, whereupon said resilient means bias said bracket into substantial coincidence with said selector; a driving roller rotatably mounted on said plate; an electric motor coupled to said driving roller; an idler wheel movably mounted on said plate intermediate and normally out of engagement with said driven wheels; means normally maintaining said idler wheel out of engagement with said driving roller; and mechanism operable by movement of said bracket under the influence of said resilient means to engage said idler wheel with said driving roller and selectively with one of said driven wheels, such movement of said bracket eiTectively engagwith the other driven wheel.

15. Magnetic sound translating apparatus comprising, in combination, a pair of spaced rotatable reels for traversing a linear magnetic recording medium with respect to a magnetic translating head; a supporting plate; a pair of friction driven wheels rotatably mounted on said plate and each operatively coupled to one of said reels; a manually operable selector pivotally secured to said plate intermediate said reels; a bracket pivotally mounted on said plate, said selector and said bracket having a common pivot center; resilient means biasing said bracket to follow the movements of said selector; a latch fixed to said plate; a latching bar on said bracket releasably engaging said latch, said latch and bar preventing movement of said bracket in response to movement of said selector; a cam on said selector engaging said latching bar, said cam releasing said bar from said latch when said selector approaches its limit of movement in either direction, whereupon said resilient means bias said bracket into substantial coincidence with said selector; a driving roller rotatably mounted on said plate; an electric motor coupled to said driving roller; an idler wheel movably mounted on said plate intermediate and normally out of engagement with said driven wheels; means normally maintaining said idler wheel out of engagement with said driving roller; mechanism operable by movement of said bracket under the influence of said resilient means to engage said idler wheel with said driving roller and selectively with one of said driven wheels; and a pair of brakes each normally engaged with one of said driven wheels; such movement of said bracket disengaging said brakes from said driven Wheels.

16. Magnetic sound translating apparatus comprising, in combination, a pair of spaced rotatable reels for traversing a linear magnetic recording medium with respect to a magnetic translating head; a supporting plate;.a pair of friction driven wheels rotatably mounted on said plate and each operatively coupled to one of said reels; a manually operable selector pivotally secured to said plate intermediate said reels: a bracket pivotally mounted on said plate, said selector and said bracket having a common pivot center; a pair of brake means mounted on said bracket and each cooperable with a driven wheel; resilient means biasing said bracket to follow the movements of said selector; a latch fixed to said plate; a latching bar on said bracket releasably engaging said latch, said latch and bar preventing movement of said bracket in response to movement of said selector; a cam on said selector engaging said latching bar, said cam releasing said bar from said latch when said selector approaches its limit of movement in either direction, whereupon said resilient means bias said bracket into substantial coincidence with said selector; a driving roller rotatably mounted on said plate; an electric motor coupled to said driving roller; an idler wheel movably mounted on said plate intermediate and normally out of engagement with said driven wheels; means normally maintaining said idler wheel out of engagement with said driving roller; mechanism operable by movement of said bracket under the influence of said resilient means to engage said idler wheel with said driving roller and selectively with one of said driven wheels; and a pair of brakes each normally engaged with one of said driven wheels; such movement of said bracket effectively engaging one of said brake means with the other driven wheel and disengaging said brakes from said driven wheels.

17. In a magazine type magnetic sound translating apparatus including a magazine containing a pair of reels for traversing a linear magnetic recording medium with respect to a magnetic translating head, spooling mechanism for layer winding the medium onto and off of the ree s and mechanical coupling means for each of the reels and for the spooling mechanism, a sound translating unit interchangeably cooperative with the magazine comprising a casing; a mounting plate mounted in said casing; a magazine supporting plate; a pair of shaft housings interconnecting said plates in vertically disposed relation: a pair of shafts each rotatably mounted in one of said housings; a coupling element on the upper end of each shaft projecting through said supporting plate for detachable cooperation with the reel coupling means of the magazine; a coupling gear projecting through said supporting plate for cooperation with the spooling mechanism coupling means; coupling gear to one of said shafts; a pair of friction driven wheels each secured to the lower end of one of said shafts; a driving roller rotatably mounted on said mounting plate; an electric motor coupled to said driving roller; an idler wheel normally mounted on said mounting plate intermediate and normally out of engagement with said driven wheels; a manually operable selector pivotally secured to said plate intermediate said wheels; a movable operator operative to selectively engage said idler wheel with either of said driven wheels and with said driving roller; resilient means biasing said operator to follow the movements of said selector; and means restraining movement of said operator in response to movement of said selector until said selector has approached its limit of movement in either direction, said last-named means thereupon releasing said operator to be biased in the same direction by said resilient means.

18. In a magazine type magnetic sound translating apparatus including a magazine containing a pair of reels for traversing a linear magnetic recording medium with respect to a magnetic translating head, spooling mechanism for layer winding the medium onto and off of the reels and mechanical coupling means for each of the reels and for the spooling mechanism, a sound translating unit interchangeably cooperative with the magazine comprising a casing; a mounting plate mounted in said casing; a magazine supporting plate; a pair of shaft housings interconnecting said plates in vertically disposed relation; a pair of shafts each rotatably mounted in one of said housings; a coupling element on the upper end of each shaft projecting through said supporting plate for detachable cooperation with the reel coupling means of the magazine; a coupling gear projecting through said supporting plate for cooperation with the spooling mechanism coupling means; reduction gearing connecting said coupling gear to one of said shafts; a pair of friction driven wheels each secured to the lower end of one of said shafts; a driving roller rotatably mounted on said mounting plate; an electric motor coupled to said driving roller; an idler wheel normally mounted on said mounting plate intermediate and normally out of engagement with said driven wheels; a manually operable selector pivotally secured to said plate intermediate said wheels; a movable operator operative to selectively engage said idler wheel with either of said driven wheels and with said driving roller; resilient means biasing said operator to follow the movements of said selectorpmeans restraining movement of said operator in response to movement of said selector until said selector has approached its limit of movement in either direction, said last-named means thereupon releasing said operator to be biased in the same direction by said resilient means; a switch secured to said supporting plate and controlling the energization of said motor; and an operator for said switch projecting above said supporting plate for cooperation with an element of the magazine operable by said reduction gearing and coupling gear, in response to-transfer of substantially all of the medium from one reel to the other, to move said operator to condition said switch to deenergize' said motor.

reduction gearing connecting said.

19. In a magazine type magnetic sound trans:

lating apparatus including a magazine containing a pair of reels for traversing a linear magnetic recording medium with respect to a magnetic translating head, spooling mechanism for layer winding the medium onto and off of the reels'and mechanical coupling means for each of the reels and for the spooling mechanism, a sound translating unit interchangeably cooperative with the magazine comprising a casing; a mounting plate mounted in said casing; a magazine supporting plate; a pair of shaft housings interconnecting said plates in vertically disposed relation; a pair of shafts each rotatably mounted in one of said housings; a coupling element on the upper end of each shaft projecting through said supporting plate for detachable cooperation with the reel coupling means of the magazine; a coupling gear projecting through said supporting'plate for cooperation with the spooling mechanism coupling means; reduction gearing connecting said coupling gear to one of said shafts; a pair of friction driven wheels each secured to the lower end of one of said shafts; a driving roller rotatably mounted on said mounting plate; an electric motor coupled to said driving roller; an idler wheel normally mounted on said mounting plate intermediate and normally out of engagement with said driven wheels; a manually operable selector pivotally secured to said plate intermediate said wheels; a movable operator operative to selectively engage said idler wheel with either of said driven wheels and with said driving roller; resilient means biasing said operator to follow the movements of said selector; means restraining movement of said operator in response to movement of said selector until said selector has approached its'limit of movement in either direction, said last-named means thereupon. releasing said operator to be biased in the same direction by said resilient means; spaced latches pivotally mounted on said supporting plate and automatically engageable with latching means on the magazine when the latter is placed on said supporting plate; and manually operable releasing means for said latches.

20. Magnetic sound translating apparatus comprising, in combination, a pair of spaced rotatable reels for traversing a linear magnetic recording medium with respect to a magnetic translating head; a supporting plate; a pair of friction driven wheels rotatably mounted on said plate and each operatively coupled to one of said reels; a manually operable selector pivotally secured to said plate intermediate said reels; a bracket pivotally mounted on said plate, said selector and said bracket having a common pivot center; resilient means biasing said bracket to follow the movements of said selector; .a latch fixed to said plate; a latching bar on said bracket releasably engaging said latch, said latch and bar preventing movement of said bracket in response to movement of said selector; a cam on said selector engaging said latching bar, said cam releasing said bar from said latch when said selector approaches its limit of movement in either direction, whereupon said resilient means bias said bracket into substantial coincidence with said selector; a driving roller rotatably mounted on said plate in alignment with such common pivot point; an electric motor coupled to said driving roller; a second bracket mounted on said plate intermediate such common pivot point and said driving roller for movement either longitudinally or laterally thereof; an idler wheel movably mounted 17 on said second bracket intermediate and normally out of engagement with said driven wheels; resilient means biasing said second bracket iorwardly of said plate to maintain said driving roller and said idler wheel disengaged; a pair of I tappets mounted on the first-named bracket; and a pair of abutments on said second bracket respectively cooperative with said tappets; movement of said bracket in response to movement of said selector selectively striking one of said tappets against its associated abutment todrive said second bracket rearwardly oi said plate to engage 18 said idler wheel with said roller and laterally 0! said plate to engage said idler wheel selectively with one or said driven wheels.

WILLIAM P. LEAR.

REFERENCES CITED The following references are of record in the file of this Patent:

FOREIGN PATENTS untry Date 

